Abstract

Molecular dynamics simulations were performed to investigate the adsorption mechanism of arg-gly-asp (RGD) tripeptide on pit and perfect rutile (110) surfaces in aqueous solution and the competitive mechanism of RGD and water. It is shown that the adsorption of RGD on pit surface is more stable than that on perfect surface, and the adsorption energy of the pit surface is , which is 1.8 times as big as that of the perfect surface.Water influences significantly RGD adsorption on the surface. The water molecules reach first the surface and occupy the adsorption sites, i.e., the water oxygen atoms bond to the surface fivefold titanium atoms to form the stable first hydration layer and interact with the surface bridging oxygen atoms to form the second hydration layer. The subsequent arrival RGD edges out the adsorbed water molecules bonding to the surface oxygen atoms and forms hydrogen bonds with these oxygen atoms. Electrostatic and van der Waals interactions are the main interactions between RGD and hydrophilic surfaces.

Received 08 September 2008Accepted 06 October 2008Published online 27 May 2009

Acknowledgments:

This work has been funded by the National Natural Science Foundation of China (Grant No. 50675050) and the Multidiscipline Scientific Research Foundation of Harbin Institute of Technology (Grant No. HIT. MD 2003. 10).